Improvement in processes for making soap



UNITED STATES PATENT OEEICE.

RICHARD A. TILGHMAN, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN PROCESSES FOR MAKING SOAP.

Specification forming part of Letters Patent No. 12,142, dated January 2, 1855.

To @ZZ 1071/0712/ it may concern:

`Be it known that LRICHAED A. TILGHMAN, of Philadelphia, Pennsylvania, have invented certain Improvement-s in Manufacturing Soap; and I do hereby declare that the following is a full and exact description thereof.

My invention consists in a method of making soap from neutral fatty bodies and carbonated alkalies by subjecting a mixture of the fat and solution of carbonated alkali to a high temperature and pressure, whereby the glycerine of the fat and the carbonic acid of the alkali are set free and the fat, acid, and alkali combine into soap. I mix the fatty body to be operated upon with from a third to a half of its bulk of water, in which is dissolved the requisite quantity of carbonated alkali, and the mixture maybe placed in any convenient vessel in which it can be subjected to the action of a temperature about the same as that of melting bismuth until the operation is complete, and the vessel must be closed, so that the requisite amount of pressure may be applied to prevent the conversion of the water into steam. The process may be performed more rapidly and also continuously by causing the mixture of fatty matter and alkaline solution `to pass through a tube or continuous channel heated to the temperature already mentioned, the requisite pressnre for preventing the conversion of the water into steam being applied during the process; and this, I believe, is the best inode of carrying my invention into effect.

In the drawings hereto annexed are shown ligures of an apparatus for performing` this process speedily and continuously, but which apparatus I do not intend to claim as any part of my invention.

Figure l of the said drawings is a vertical section of this apparatus, and Fig. 2 shows the various parts of the apparatus in horizontal section. f

Similar parts in the figures are marked with similar letters of reference.

I place the fat or oil in a fluid state in the vessel c, with from one-third to one-half of its bulk of warm water, in which is dissolved the requisite quantity of carbonated alkali. The disk or piston o, perforated with numerous small holes, being kept in rapid motion up and down in the vessel c, causes the fat or oil and alkaline solution to form an emulsion or intimate mechanical mixture. A force-pump c, like those in common use for hydraulic presses, then drives the mixtureA through a long coil of very strong iron tube cl d CZ, which, being placed in a furnace e c, is heated by a re f to about the temperature of melting bismuth. From the exit end g of the heating-tubes d d, the mixture, which has then become converted into soap, solution of glycerine, and free carbonio acid, passes on through another coiled iron tube h h 7i, immersed in water, by which it is cooled down from its high temperature to below 212 of Fahrenheits thermometer, after which it makes its escape through the exit-valvei into the receiving-vessel. The iron tubes I have employed and found to be convenientfor this purpose are about one inch external diameter and about half an inch internal diameter, being such as are in common use for Perkinss hot-water apparatus. The ends of the tubes are joined together by welding to make the requisite lengths; but when welding is not practicable I make use of the kind of joints used in Perkinss apparat-us, which are now well known. rlhe heating-tube d d d is coiled several times backward and forward, so as to arrange a considerable length of tube in a moderate space. The different coils of tube are kept about one-quarter of an inch apart from each other, and the interval between them is filled up solid with cast-iron, which also covers the outer coils or rows of tubes to the thickness of half or three-quarters of an inch, as shown in Fig. 2. This casing of metal insures a considerable uniformity of temperature in the different parts of the coil, adding also to its strength and protecting it from injury by the fire. The said valve t' is so loaded that when the heating-tubes d d d. are at the desired working temperature and the pump c is not in action it will not be opened by the internal pressure produced by the application of heat to the mixture, and therefore when the pump c is not in action nothing escapes 'from the valvez' if the temperature is not too high; but when the pump forces fresh mixture into one end j of the heating-tribes d d cZthe exit-valve i is forced open to allow an equal amount of the mixture which has been operated upon to escape out of the cooling-tubes h 7L at the valve t'. No steam or air should be allowed to accumulate in the tubes, which should be kept entirely full of the mixture. For this purpose, whenever it may be necessary, the speed of the pump should be increased, so that the current through the tubes may be suiiiciently rapid to carry out with it any air remaining in them. I prefer that the pump c should be worked at Stich a rate in proportion to the length or capacity of the heating-tubes d d that the mixture while owing through them should be maintained at the desired temperature for about ten minutes before it passes into the cooling part 7L h of the apparatus. At about 350 Fahrenheit neutral fats Will form soaps with solution of carbonated alkalies, but a higher temperature will produce the result more quickly. Palm-oil has been found to Work well at a heat between the meltingpoints of tin and bismuth. Tallow requires a rather higher temperature for quick working. If the heat is unnecessarily high, a disagreeable smell is produced in the soap, and some fats-such as palm-oil-acquire this at lower heats than others. By starting the apparatus at a low heat and gradually increasing it the temperature giving the best product with the fatty body employed can easily be determined.

To indicate the temperature of the tubes d d d, I have found the successive melting of metals to be convenient in practice. Several holes half an inch in diameter and two or three inches deep are bored into the solid parts of the casting surrounding the tubes, each hole being charged with a different metal. The series I have used consist of tin melting at about 440C, bismuth at about 5100, and lead at about 612. A straight piece of iron wire passing through the side of the furnace to the bottom of each of the holes enables the Workman to feel which of the substances are melted and to regulate the fire accordingly. It is important for the quickness and perfection of the action that the oil and alkaline solutions during their entire passage through the heating-tube should remain in the same state of intimate mixture in which they enter them. I therefore prefer to place the series of heating-tubes in a vertical position, so that any partial separation which may take place while the liquids pass up one tube may be counteracted as they pass down the next. I believe that it will be found useful to fix at intervals in the heatingtubes of such apparatus as may admit of such an addition diaphragms pierced with numerous small holes, so that the liquids being forced through these obstructions may be thoroughly mixed together. I deem it prudent to test the strength of the apparatus by a pressure of ten thousand pounds to the square inch before taking it into use; but I believe that the working-pressure necessary for producing the heat I have mentioned will not be found to exceed two thousand pounds to the square inch. Then it is desired to diminish the contact of the liquids with iron, the tribes or channels of the apparatus may be lined with copper.

If resinous or other matters are intended to be usedin the manufacture of the soap, they may be dissolved either in the alkaline solution or the oil or may be combined with the soap after it has left the apparatus.

The carbonio acid expelled from the alkali by this process when performed in the apparatus above described escapes as the soap issues from the exit-valve. If butlittle water has been used and the quality of the soap is suiiiciently good Without further purification, it can be put into frames to harden at once, or it may be put into the coppers, boiled up, separated from the glycerine, and finished in the usual manner.

What I claim as my invention, and desire to secure by Letters Patent, is-

The manufacturing of soap by subjecting a mixture of fatty matters and solution of carbonated alkalies to a high temperature and pressure, as described.

R. A. TILGHMAN.

IVitnesses:

JAMES MCGURLEY, JOHN R. DACKEP.. 

